I can't argue you there, as I agree about them jumping ship on the old cast (not sure why they did that), but at least the main character was not another soldier or scientist. Not to mention he was related to the awesome Chujo from Mothra. Other highlights to SOS are its monster battles, Mothra costume (the best since the original IMO), the music, and effects. OMG, the miniatures are absolutely fantastic. Also, I'm glad Godzilla no longer just stands there lifelessly to get pummeled by missiles.
Sometimes I do think both Kiryu movies might have benefited had their run times been 15 minutes longer like their predecessors, especially SOS, but other times I think maybe being 88 and 91 minutes was perfect so that it didn't drag out pointless scenes. If there is one thing I have learned from watching Sentai over the years, is is how amazingly a four minute difference can make an episode. Half of my favorite Sentai series are those that run about 17 minutes when you take out the opening and ending credits (Dai, Kaku, Zyu, Jet, Car) as they feel fast paced and do not drag, while all of the series that are 21 minutes long without the credits at times can feel like they are dragging, even episodes from my favorite series.